In a packet switching network, a packet of information is routed from a source to a destination by using a destination address contained in the packet. Packets of information are multiplexed onto network pathways. No particular path is reserved for data in a packet switching network, and a packet can generally take any path in the network. While a packet is not limited to any particular path, techniques exist for routing a packet based on certain criteria, such as speed, cost, distance, and Quality of Service (QoS).
An additional type of network that is becoming common is a label switching network. A label switching network runs in conjunction with a packet switching network, and uses labels placed into packets in order to route packets. Normal routing procedures for packet switching are disabled. A “tunnel” is created to connect a source with a destination. The appropriate labels are selected for packets emanating from the source and entering the network so that the packets follow the tunnel and end up at the destination. Label switching offers the benefit of providing tunnels for packets. Consequently, packets should arrive at the destination at more regular intervals, which is important in certain time-sensitive applications such as real-time audio and video.
Packet switching and label switching networks both are helped by methods that route demands on these networks. These methods can be used real-time, meaning that changes are made to the network in order to more efficiently route demands on the network, or can be used to determine when or how the network should be upgraded to support new demands. Problems with methods used to solve network routing are that they are complex and time-consuming. A need therefore exists for techniques that solve these problems.